One in nine women suffer from pelvic floor dysfunction, including urinary incontinence and vaginal wall or uterine prolapse (VUP). Stress urinary incontinence (SUI) affects 38% of women over the age of 65 years and over 13 million women in the United States. Pelvic muscle strength is commonly assessed in these patients. However, current measurement techniques are either subjective or produce artifact, due to their non-isometric nature or contamination by intraabdominal pressure. During Phase I, we developed a second generation system that measures the isometric strength and contractile properties of female pelvic floor muscles. The system centerpiece is a novel intravaginal transducer that differentiates between intraabdominal pressure and levator ani force. During Phase II, system mechanics, electronics and software will be refined to improve system sensitivity, accuracy, and ease-of-use. Laptop- and Personal Data Assistant-based systems will be developed and validated. Clinical device performance will be confirmed by testing the null hypothesis in 120 women (40 healthy continent, 40 with VUP, 40 with SUI) that localized pelvic floor muscle defects visible on MR scans will correlate with pelvic muscle weakness. The system allows assessment of pelvic floor function and exercise intervention efficacy, and can provide biofeedback and adherence data during training.